NDMP restore is failing with block read is not a NetBackup or Backup Exec media header

We are trying to validate a recently configured EMC filler backups. We are restoring the data from full backup to the same filler. But all the restores are failing, from differnt tapes and different images. We tried to do image verifcation, that also showing errors. So far, we tried from three different tapes, no luck.

Its mounting the tapes, but not even reading

Job detail :-

11/30/2012 21:32:05 - begin Restore

11/30/2012 21:32:05 - number of images required: 1

11/30/2012 21:32:05 - media needed: HH0377

11/30/2012 21:32:09 - restoring from image hhccha-vnx-cs0_1353665318

11/30/2012 21:32:12 - Info bpbrm (pid=22507) hhccha-vnx-cs0 is the host to restore to

Let's keep the filler aside for a moment.
Are you able to restore everthing else without any problem? I mean the normal backups which were not of filer.

If only filer is failing then what kind of tapes you are using for NDMP backup? Is the policy type NDMP? Have you backed them up with the same environment? Can you backup the filer now without any issues?Tape and drive density matches? Is the physical barcode changed on the tapes?

This error comes when NBU is not able to read the tape header.When you loaded a volume for a backup or restore, the tape manager (bptm), did not find the expected tape header. This error can mean that a robotic device volume is not in the slot number that is in the Media and Device Management volume configuration. It also can mean that a read error (I/O error) occurred. If the tape has been out of the tape library since the backup was written, there is also the possibility that the tape has been used for some other purpose and has been overwritten with non-Netbackup data

Recommended action:

•If the volume is in a robot that supports bar codes, verify the robot contents by using a robot inventory option.
•If the volume was mounted on a nonrobotic drive, verify that the correct volume was mounted and assigned.
•Check the NetBackup Problems report. If it shows a fatal read error, attempt the operation again with another drive, if possible.
•If your configuration has multiple servers or HBAs with access to your tape services, make sure the SCSI Reserve or Release is configured correctly. (Most likely, the tape services configuration is an SSO configuration.) For more information, refer to the NetBackup Shared Storage Guide